Train control



I S p 8 1926.

' C s. BUSHNELL TRAIN CONTROL Filed March 25 5 MP in u 3 o w. 9. 8 0b Qvw m 5 F s. 3 H J a w a a 3 w '8 m* x 3 3 m v m E 3 Wm lumm m. w v m: mml ax s m 2 Q mm wm om S 3 mm m2 m3! mm L. 5 5 mm 8 m N F V n u A u T M 8m5 m T. w

B N mm NS a: mm mS I?atented Sept. 28, 1926.

UNITED STATES PATENT OFFICE.

CHARLES S. BUSHNELL, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAIL-VIAY SIGNAL COMPANY, OF GATES, NEW YORK, A CORPORATION OF NEW YORK.

TRAIN CONTROL.

Application filed March 25, 1922. Serial No. 546,711.

This invention relates to train control sys tems, and particularly toparts and circuits for governing apparatus of the cyclic type.

In train control systems of the cyclic type,

that is, systems in which a certain cycle 0t permissive speed isenforced in certain parts of each block when the nextblock in advance isoccupied or is in danger due to some other hazard, it is desirable toinitiate apparatus for causing the permissive speed and to provide otherdevices to restore or reset said apparatus atvarious points in the blockas soon as the traffic conditions in the next block change. This isdesirable because a train running in a clear block should have its speedlimited as soon as traflic conditions in. the next block in advancechange due to causes, such as, a broken rail, an open switch, theentrance of a train from a siding, and the like; and further becausetrains running under the control of a permissive speed deviceshould berelieved of such control, and allowed to accelerate as soon as thedanger conditions clear up, that is, an intermediate release isdesirable. Influences for causing such control are preferablytransmitted from one device along the trackway to another on the vehiclethrough an intervening air gap, rather than by physical contact betweensuch devices. Inductive devices which are constructed on the side ofsafety are preferably employed for communicating such influences.

lVith such and other requisites in mind, the principal objects andpurposes of the present invention are to provide devices working on thecorrect principle, namely, devices which work on the side of safety,that is, so that a failure, such as a break in a circuit, will have thesame effect as a danger influence to limit the speed of the vehicle, andwill also cause a failure to reset the device, and to construct suchdevices with the least number of parts.

More specifically, the objects and purposes are to provide influencetransmitting devices which will start to impose a restriction on thespeed of the train, and give a warning at any one of a plurality ofpoints in a block when a dangerous condition arises, and which isadapted to reset or remove the imposed restriction at any one of thesame points in the block when thedanger traflic conditions clear up; andfurther to transmit such influences through an intervening airgapinductively by inert track devices (dcvices which do not require anyenergy when either in their influence transmittingor dormant condition),and suitable cooperating devices carried by the vehicle.

Other objects and advantages of the present'invention will appear as thedescription progresses.

In describing the invention in detail. reference will be made to theaccompanying drawing, in which H Fig. 1 illustrates trackway apparatusof one form of train control system embodying the present inventionsuperimposed upon a typical form of block signal system; and

F ig. 2 is a diagrammatic and perspective view of a car-carriedapparatus embodying the present invention, which has been shown in amanner to make it easy to understand the invention. rather than to Showthe construction preferably employed in practice.

Traclawag structurc.1n the embodiment of the invention illustrated, thetransmission of the desired control influences is produced by trackelementswhich are governed in accordance with traflic conditions.Various arrangements of trackway circuits suitable for this purpose maybe employed, and it should he understood that the arrangement shown inFig. 1 is only a typical illustration. Referring to Fig. 1, the trackrails 1 of the railroad track are divided into blocks by insulatedjoints 2, one block I with the adjacent ends of two other blocks H and Jbeing shown. The parts and circuits associated with the various blocksare the same, and for convenience will be given like referencecharacters with distinctive exponents. Each of the blocks is providedwith a track bat tery 3 and a track relay 4:, the same as in ordinaryblock signal systems. My invention may be used with or without the usualfixed signals, dependent upon the type of train. control apparatus; andI have illustrated such fixed signals S conventionally, withoutattempting to illustrate their wel known control circuits and devices.

A plurality of track elements T are employed in each block, which may becontrolled by traffic conditions in advance or may be in their activecondition permanently on account of a'permanent hazard in advance ofsuch block. These track elements T of my invention, in general, comprisea magnetic yoke or core and an associated coil,

yoke. These track elements T are intendedto transmit control influencesor impulses to a passing tram at a plurality of control points in eachblock in accordance with tratfic conditions in the next block inadvance;

In. the embodiment of the invention illustrated-in Fi 1, a plurality ofequally.

spaced track elements T are employed in a manner so that=thelasttrackelementis a. shortdistance from the exit end of the block,or'th'e point at which the trainis to come to a predetermined minimumspeed. Adjacent each i th'ese'track elements is providedarepeater-relayRR for making the track elements active or inactive, de pendent uponwhether the repeater relays are energized or deenergized. The repeaterrelays are normally energized through a front contact 10 of the trackrelay 1 o f th'e next block in advance. Although the e re peater relaysRR- may be connected in or in multiple, they have been shown connectedin series for convenience. This cir- Quit may be traced astollows:-Beginningthe block, dependent upon the length oi":theparticular block as compared with the distance required for thecyclic device, which is to cooperate therewith, to pertorn-i itsfunction, the remaining elements being equally spaced at fixedintervals, the distance between these elements being dependent upon thecar apparatus which isto cooperate therewith.

Oar apparatuc.Tl1e several devices 01" the car apparatus illustrated inFig. 2 will first be separately described, afterwhich their operation inthe particular system in which they are used will 'be described. The carelement L comprises a U-shaped-core. 12 terminating in pole pieces. 13..On one: of the legs is provided aprinr. y coil 1?, the other leg beingprovided with a secondary. coil S. The car element L isp'referab'lvmounted on the truck eta railway vehicle. in a manner to protect it fromiars andvi bration and flOillSllOW and ice in any suitable'inanner. Thecarelenient is'preterably solocatedlthat its'pole piecesl'S pass adiacent the pole piecesootfthe tract: elements 1, the vehicle'inoves alongthe trackway. A; control" relay CR" and auxiliary an;

A are employed,which-are constructed so that their moving parts are wellbalanced to prevent a false actuation thereof, due to jars and vibrationcaused by the moving vehicle. Although these relays have been shown asbeing the same, the illustration is merely conventional and in practicethe control relay CR will be responsive to a much smaller current andoperates smaller contacts than does the auxiliary relay A.

A cam starting magnet CS for setting the cyclic system into operation isemployed. This cam starting magnet compriseswindings 1 1 and 15supported on a Ueshaped yoke 16. Aniarmature 1'7 normally held away fromthe yoke 16 by a spring-18B connectedto thecollar 19 byxa bifurcated lug20. hen the cam starting/magnet CS isenergized; the cyclic SYStBHLlSheld 'in its normal andineitlect-ive position, whereasit this camstartin magnet CSis-deenergized; i118 cyclic system will be actuated-ateprovice a continuing decreasing permissive speed Tl'ie'speedcontroldevicesot the car-carried apparatusillustrated may take any one of thevarious fo ms usually employed.

For convenience the specific type of cyclic control system shown by thepatentlto Simmen, 1,150,309, granted Aug.- 17, 1915 has beenillustrated.

The speed control devices include a centrit'ugal device driven bybeveled gearsflll and 21 from the wheels'oit avehicle. This centrifugaldevice has been-illustrated in conventional manner. and comprisesvertical shaft 22 supportedin a bearing; 28; the shaft is connectedtothe'beveled gear 21 and has pinned thereto a cross bar 2 3 connectedto a slidab-lecollar 24 by two pairs of links 25; Each pair ot'links ispivot-ally connectecL t" a centritagalweight- The slidable collar isbiased away from the cross bar 23 by a springQ'Z. It will be noted thatthe collar-Qlwillbe movedto various positions on the shaft 22, due tothe centrifugal force of the weights 26 acting against the spring-27 asthe shaft 22 is-ro tated. I

At the end of'th e shaft 22 isprovided a beveled gear 2,9 continuouslyin-uiesh with the gear 30 which is pinned to ashaft 31, having its oneend'supported'in a bearing 32. The other endot theshatt'ill. is-rotatably supported in the collar19." Near the collar 19 the sha'ttfill isprovided with worm 32, which is arranged to 'operatively engage the wormwheel 33' when the cam starting magnet CS is deenergizedi This wormwheel rigidly connected" to a shaft supported" by bearings- {not shown),and; is provi led", with projecting lucgfio. Adjacent tli shaft isprovided a nanny sta es; The;coilspriiig.f37 on the shaft has ltSGde""fi te l l 'g' 0110p posite sides of the stop 36, which ends, projectabove the stop 36 a distance to pass on opposite sides of the lug 35,whereby the worm wheel 33 is biased into its normal position asillustrated.

On the shaft 3 1 is keyed a reset contactor X. This reset contactorcomprises a disc 38 of insulating material provided with contacts 40,41, 42, 43,4 1, 15, 50, 51, 52, 53 and 54. spaced and located in amanner as will appear when the operation of the apparatus is described.Adjacent the reset contactor X is provided an insulating block 55, towhich are fastened brushes or contact fingers 56, 57, 58 and 59 adaptedto be connected by the contacts on the insulating disc 38. On theperiphery of the insulatingdisc 38 is secured a cam 60 in any suitablemanner. This cam 60 is adapted to connect the spring contact 61 with thecontact 62 when the reset contactor X is rotated substantially one-halfrevolution in either direction.

To the insulating disc 38 is bolted a cam 63. The slidable collar 24 ofthe speed responsive device is provided with a groove in which iscontained the bifurcated end of an angle lever 64, which is pivotallysupported on the pin 65. The other end of the angle lever is bifurcatedand connected to a floating lever 66 by a pin 67. The other end of thefloating lever 66 is provided with a bifurcation in which is pivotallysupported a roller 68. At an intermediate point on the floating lever ispivotally fastened a link 69, which has its opposite end connected to anarm 70 of a sector 71 by a pin 72. This sector 71 is biased by a spring7 3 in a direction to urge the roller 68 against the cam 63.

The working face of the sector 71 comprises concentric surfaces 74, 7 5and 76, the pur poses of which will be pointed out hereinafter.

Against the working surfaces of the sector 71 is biased a roller 77pivotally secured to the contact finger 78 in any suitable manner. Undernormal conditions, that is, when the roller 77 is in contact with thesurface 7 1, the contact finger 78 will be forced against the contactfinger 79, which in turn will be biased against the contact finger 80.

In order to advise the engineer when the railwayvehicle has almostreached the permissive speed, a warning signal W has been provided. Thiswarning signal comprises a whistle 81 adapted to be controlled by anelectro-pneumatic valve 82, which will connect the whistle with a supplyof pressure fluid through the pipe 83 when the electropneumatic valve 82is deenergized.

Another warning signal has been provided which comprises a bell 84.connected in series with a green lamp G through a battery 85 in acircuit which may be traced as follows :Starting from the battery 85,wire 86,

bell 8 1, wire 87, lamp Gr, wire 88, back to the battery 85. A normallyopen switch comprising the stationary contact 89 and the movable contact90 is positioned adjacent the collar 19, so that when the collar is inits lower position the contacts 89 and 90 will be closed, thuscompleting a circuit for shunting the lamp, thereby connecting the bell84 directly across the battery 85, which will allow sufficient currentto flow through the bell 84 to cause it to sound. This circuit may betraced as follows :Beginning at the battery 85, wire 86, bell 84, wires87 and 91, contacts 90 and 89, wires 92 and 88, back to the battery 85.

Means have been provided for applying the brakes as illustrated by thebrake applying device K which has been shown conventionally as anelectro-pneumatic valve. This brake applying device K embraces provisionfor limiting the amount of reduction of brake pipe pressure when anautomatic brake application is made, and prevents the engineer fromrecharging the brake pipe to prevent such a brake application takingeffeet, all in conformity with well recognized air brake practice. Thisbrake applying device K when deenergized will apply the brakes of thevehicle, and when energized may automatically release the brakes orpermit the brakes to be released by the engineer manually. A resetswitch for resetting the brake applying device under certain conditionshas been illustrated in a simplified and conventional manner by a pushbutton 93.

Opemtd0n.1n the trackwa-y system illustrated in Fig. 1, the trackelements T in the rear of an unoccupied block are in their clear trafiiccondition, because their coils 7 are in a closed circuit of lowresistance. The track elements T in the rear of an occupied block areopen circuited, and are therefore in their effective or influencetransmitting condition. This is due .to the fact that the circuit forenergizing the repeater relays RR has been opened at the front contact10 of the track relay in the block in advance. In an occupied block, thetrack elements T may be in their open or closed circuit condition,dependent upon whether or not the block in advance is occupied, ordanger exists due to some other cause.

Vith the car-carried apparatus in its nor mal condition, that is, withthe vehicle moving in a block when the next block in ad vance is clear,the primary or exciting coil P of the car element L, which is connectedin series with the brake applying device K, is included in a circuitwhich may be traced as follows :-Beginning at the terminal B of abattery, wire 121, reset switch 93, wire 94, contact fingers 79 and 7 8,wire 94, brake applying device K, wire 95, primary coil P, wire 96, backto the common return wire C. lVith this latter circuitenergized, theprimary coil P produces a magneto-motivefo*ce in the car element'Ltending to send flux through the secondary coil S on the other leg ofthe car element. This-magnetomotive-force will, however,only produce avery small amount of flux in the secondary coil Son account 'of thelarge reluctance due to the-air gap between the pole pieces 13.

The control relay GR is normally energized through a stick circuit,which may be traced as follows :Beginning at the terminal B ofa-battery, wire 97, front contact 98 of the control relay CR, wires 99and 100, winding of the control'relay CR, wire 101, secondary coil S,wire 102, back to the common return wire C.

lVith the control relay GR in its energized condition, theauxiliaryrelay A will be encrgized through a stick circuit, which maybe tracedasfollows :Beginning. at the-terminal B of a battery, wire 103, frontcontact t'ofcc-ntrol relay CR, wi es 105 and 10-6, front cont-act'10i ofthe auxiliary relay A, wires 108-and 109, winding of the auxiliaryrelay, wire 110, back to the common return wire-C.

lVith the auxiliary relay-A in its energized condition, an energizingcircuit for the cam starting magnet CS may be traced as fol lows:Begininng at the terminalof a battery B, wire 11', frontcontact 112 ofthe auxiliary. relay A, wire 113, windings 1% and 15of the camstartingmagnet CS, wire 11&, to the common return wire-C.

Assuming now that the railway vehicle is movingalOng the track in itsnormal conditionas illustrated in.Fig. 2, with the worm 32" disengagedfrom the worm wheel 33, acertain maximum .pern'iis sivespeed will. beallowed. If the engineer increases the speed of the train, the slid-ablecollar 21 will be moved up onthe shaft 22 by the action of thecentrifugal weights .26. This willcause the angle lever 6% to be tiltedin a direction to tension the link 69, thereby eventually causingthesector 71 to turn a sufficient distance to allow the roller 77 tofall upon the surface 75.

As the roller 77 rides off of the surface 74 on tothe surface 75, thecontact fingers 78 and 79 are both moved toward'the left to breakthecontact between the spring fingers 79 and 80. This will cause the warning signal 1V to be sounded, thereby informing the engineer that thepermissive speed has been reached. If new the engineerstill furtherincreases the speed of thevehicle, the roller 7'? will ride from thesurface onto the surface 76. This will cause the spring finger78 to movefrom the. spring finger 7 9, thereby interruptingjthe circuit'throughthe brake applying device K, and applying the brakes inamanner asheretofore described.

Assume now thata railway vehicle with its train control apparatus in itsnormal condition, and traveling atta speed below' the maximum permissivespeed, is entering a caution block. As the car element L passes over thefirst of the series of track elements T, these track elements being intheir open circuit or danger condition because the block in advance isoccupied, causes a momentary increase of flux through the car element L,which will decrease to its normal value when the carelement L recedesfrom the track element T. This sudden increase and decrease of fluxthrough the car element L in dnces a voltage in the secondary coil Ssimi lar to that of'a single cycle of alternating current, the secondarycoil S being wound and connected so that the first wave of uni.-cyclic'E. M. F. will oppose the volta e of the battery in the secondarycircuit. This opposing E. M. F. will decrease the current nori allyflowing in the'control relay CR to a value to drop its armature, therebyinterrupting its stick circuit and permanently deenergizing the controlrelay until it is re set by some other means.

ihe dcenergization. of the control relay CR- deenergizes the auxiliaryrelay Aby the interruption of the stick circuit of the auxiliary relayatthe front contactl the control relay CE. The dropping of the auxiliaryrelay A de'energizes the cam start ing magnet US by interrupting its ci.it at the front contact 112 of the auxiliar 3 lay. The deenergizationof the camstarting magnet CS causes the spring 18 to press the wormagainst the worm gear 33, thus causing the worm gear 33, reset con actorX, and cam 63 to be rotated in acco lance with the movement of the trainale Y track. The deenergization of the cam is ing magnet CS also causesthe collar to move the spring contact against the stationary contact 89,thereby shin the green lamp G and sounding the bell to apprize theengineer that the yclic system is in operation.

After the reset contactor X has moved a short distance in the clockwisedirection, it causes the contact 50 tobridge the brushes 56 and 57,thereby completing a pick-up circuit for the control relay CR, which maybe traced as follows :Beginning at the battery B, wire 115, contactbrush 5?, contact strip 50, contact brush 56, wires 116, 11'? and 100,winding of the control relay (5R, wire 101, secondary coil S, wire 102,to the common return wire C. This causes the control relay CR topick-up, thereby closing its front contact 98 and completing its pick-upcircuit heretofore traced.

As the train advances in the bloc-l between the first and secondftrackelements T, the reset cont-actor X is turned to some point so'that'thecontact brushes 56 and 5'? will be in" contact with the insulating, discbetween the contacts- 50' and 1,, thus setting up acertain permissivespec dependent upv D J Li on the condition of the cam 63, this cam 63being shaped so that it gradually decreasing permissive speed is imposedupon the em gineer which may conforinto any particular speed distancecurve, for instance, it may I conform to the speed distance brakingcurve of the particular vehicle under a service brake application. Ifthe engineer exceeds this permissive speed, the whistle 81 will besounded, and the brake applying device is: will be actuated insubstantially the same manner as heretofore described.

Assume now that the second track element T of the series of elements in.the particular block in question is passed over. As the vehicle passesby this second track element T, the control relay CR will again be mementarily deenergized, thereby breaking its stick circuit insubstantially the same man ner heretofore.

Assume now that the train is proceeding between the second and thirdtrack element,

the cam 63 being gradually rotated, thus enforcing a graduallydecreasing permissive speed. As the contact disc reaches a position sothat the contact strip 51 bridges the contact brushes 58 and 59, nothingparticularly will result, because the circuit completed by these contactbrushes is open at the front contact 10-1 of the control relay CR.

Assume now that the vehicle proceeds in the block until the contactbrushes 56 and 57 are bridged by the contact strip 52. This will causethe control relay CR to be picked up, thereby completing its stickcircuit through its front contact 98 in substantially the same manner asheretofore described.

Assume now that the. train is proceeding between the second and thirdtrack element T of the series of elements in the block,aud that trahicconditions inthe block in advance clear up. As the third track elementof the series of elements is now passed over, it being in its closedcircuit or clear trafiic condition, because the track relay 4 of theblock in' advance and likewise the repeater relays are energized, noappreciable voltage will be generated in the secondary coil S of the carelement. This is accounted for by the fact that a slight change of fluxthrough the track element T causes a large current to flow in thewindingv 7 connected in a circuit of low resistance. This current bywelhknown principles of alternating current flows in a direction tooppose the :lux which produces it. Consequently, only a very smallamount of flux will traverse the track element T, and likewise only asmall change of flux will take place in the car element L, thus inducingonly a very nnall voltage. This small voltage induced in the circuit,including thecontrolrrlay CE, is insuflicient to cause the control relayto drop.

Assume now that the train continues to travel between the third andfourth track element of the series illustrated, thereby continuing agradually decreasing permissive speed to a point where the contact strip53 bridges the contact brushes 58 and 59. This completes a pick-upcircuit for the auxiliary relay A, which may be traced as followsStarting from the terminal B of a battery, wire 103, front contact 104of the control relayCR, wires 105 and 118, contact brush 58, contactstrip 53, contact brush 59, wires 119 and 109, winding of the auxiliaryrelay A, wire 110, to the common return wire C. The energization of thispick-up circuit causes the auxiliary relay A to be permanent- 1yenergized through its stick circuit heretofore traced, and furthercloses the energizing circuit of the cam starting magnet CS, therebyraising the worm 32 away from the worm gear 33, thus allowing the spring37 to return the worm gear 33, the reset contactor X, and the cam 63 totheir original and normal position.

The energization of the cam starting magnet CS allows the spring contact90 to leave the contact 89, thereby illuminating the green lampG, anddecreasing the current through the bell 84: to an extent to silence thesame.

The sequence of operation in passing over succeeding track elements whenall these track elements are in their danger or open circuit conditionat the time they are passed over is repeated until the last trackelement of th-e'series is passed, thereby gradually reducing thepermissive speed to a certain low maximum value, for instance, such asfifteen miles per hour. If the vehicle continues to move along at thislow permissive speed until the worm gear 33 has turned through an arc ofsubstantially 180 degrees, the worm gear 33 will be stopped. on accountof'the mutilated portion 120 which does not allow the worm to furtherrotate the worm gear on account of the absence of teeth at the mutilatedvpart. lVith the worm gear in this position, the cam 60 will be in aposition to hold the springcontact 61 against the stationary contact 62.lVith these contacts in thisposition, the engineer, being fully aware ofthe trafl ic conditions, may now remove the restrictions imposed bythetrain control apparatus by pushing reset switclr93, thereby closing areleasing circuit which may be ,traced as follows Beginnin at theterminal B of a battery, wire 121, reset sw ,eh 93, wire 122, contacts61 and 62, wires 1 3, 117 and 100, windingof the control relav CR, wire101, secondary coil S, wire 102, thus picking up the control relay CR--The energization of the control relay will cause the auxiliary relay Ato be energizedthrough a circuit which may be traced as follows:-Beginning at the terminal B or abattery, wire 103, front contact 10-1of the control relay CR, wires 105 and 11S, contact brush 58, contactstrip 45, contact-brush 59,

wires 119 and 1G9, winding ofthe auxiliary relay A wire 110, to thecommon return wire C. The energizaation of the auxiliary relay A willenergize the cam starting mag net CS, which will allow the cyclic systemto return to its original position by the aid of the spring 37. p

In order that the present invention may be applied to enforce safelimiting speeds at points ina block where permanent hazards exists,suchas, dangerous curves, approaches to sudden down grade, bridges, yardlimits, etc, some of the trackelements may be permanently put in theirdanger or influence emitting condition. This may be done by ving theircoils 7 open circuit-ed, or by omitting thenr altogether. For instance,suppose that passingtrains should not be permitted to enter a certainblock at more than, say 1-0 miles per hour, under any con dition, andassume that-such a speed limit will be enforced by the particular carapparatus used when two danger track elements have been passed over. Toenforce sucha speed limit for all trains of a class, regardless ofwhether or not the next block in ad vanee is occupied, the last twoelements of the block in the rear should be permanently in theirinfluence transmitting condition. Vi it-h an arrangement of this kind,the second last track element of the block in question would start thecam under clear trafiic conditions, thus bringing the speed down to thedesired amount after which an automatic release would take place in amanner as already explained. If, however, theblock in advance wereoccupied, the cam would be initiated at the first element ofthe seriesof track elements employed and enforce permissive speed limits in theusual way. If a higher permissive speed than 40 miles per hour, as justexplained, is'desired on account of some pcrmanenthazard at the entranceto a block, only the last track elementof the block in the rear isconstructed to be permanently active, and in this event the canalsinitiated by the deenergization of the relays CR and A when passing bythe lasttrack element. The control relay GR is again picked up whencontact fingers 56-and 57 are bridged by contact 50,- and the auxiliaryrelay A, and in turn the camstarting magnet CS, are energized when thecontact fingers 5S and 59 are bridged bythe'contact 51, so that therestriction is removed upon en tering the following block, assuming thisfollowing block to be clear. If, however, this following block is acaution block and the first track element in this block is spaced thesame distance from the last element of the preceding block asjthat ofthe spacing between successive elements in the same block, a furtherrestrictionin the spe'edre sults as more clearly brought out in theoperation of the system. On the other hand, if the first track elementin this following block is located so far in advance of the last element of the block in question that the contact 51 bridges spring fingers58 and 59, the cam will again be reset, as already explained, but willagain be initiated when the first track element of the following blockis reached. 7

l t should be noted that contacts 4-0 and l1, similarly to the contacts50 and 5%, have been provided on the opposite side of the insulatingdisc 38. These contacts are provided so that if the vehicle is changedend for end in those types of systems where a car element is provided oneach side of the vehicle, the proper circuits are closed inpropersequence when the locomotive is traveling tender ahead. i

It should be understood that any number of track elements maybe employedin a se ries in each block, since all that'is required is that they beof a proper number and properly spaced to correspond to the spacing ofthe contact strips on the reset contactor X. For instance, the trackelements are so spaced that the second element is passed over aftercontact 50 has bridged the contact fingers 56 and 57 but before contact51 bridges contact fingers 58 and 59. It is, however, desirable to spacethe track elements of a series equally, and start such series'at a pointin the block so that the cam will enforce the low limiting speedheretofore mentioned before the train reaches the end of the block.Although the cam 63 has been illustrated as being circular andeccentrically mounted, this cam is preferably shaped to enforce apredetermined brake application curve at each point during its movement,that is, to enforce a predeterm ned speed such that if the train exceedsit, the brakes will be applied-in time to stop the train before itreaches the end of the block.

In the embodiment of the invention illustrated, the simplest form ofcyclic permissive speed enforcing apparatus has been illustrated. Thishas been done to make it easy to understand the invention as applied toa cyclic tvpe of train control system generally It should, however, beunderstood that a plurality of cams may be used, of which a particularone is selected for a particular'block instead of using the single camillustratedfor all blocks, suitable selecting means being employed'forthis purpose; or any other means may be used'to modify the effect of agiven camby employing variable lever arms, changeable gear ratioapparatus and various other devices used for varying thepermissive speedenforced by a cam, depende'nt'upon the character of the particular blockin which the device is used at the time.

One of the characteristic features of this invention, which will bereadily understood in view of the foregoing description, is that thebrake control apparatus on a train will be set into operation at anintermediate point in any block, in the event that, after said trainentered that block, danger conditions are created in the block next inadvance, due to a train backing into that block, the breaking of a rail,the opening of a switch, or the like. Upon such change from safe toclangerous trafiic conditions in the block next in advance, the relaysRR are deenergized, opening the circuit to the coil 7 of each of trackelements T of the block next in the rear, so that the brake controlapparatus on a following car is automatically set into operationirrespective of the signal indication at the time said train entered theblock, the instant it asses the next track element. In other words, thesystem of this invention provides not only intermediate release orrestoration, but also intermediate initiation or: operation, of thetrain control equipment of a train in a block.

If, while a. train is moving at an intermediate point in a block, thisblock changes from a clear to a caution block, possibly becauseanother'train has backed from a sec ond block in advance into the blockin advance, the car-carried cam mechanism is initiated at the next trackelement which may be the second or third, or. even the lastelement inthe block, and under this condition the train is restricted in the usualway providing the train which backed up did not back up far enough toleave the second block entirely, that is, both the track elements in theblock in question and the track elements in the first block in advancethereof are active. This will cause the permissive speed to be graduallyrestricted; proceeding, of course, on the assumption that the lastelement in one block and the first element of the next block in advanceare spaced the same distance as are the successive elements within suchblocks. so that, the last element of one block and the first threeelements of the next block in advance form a series the same as the fourelements of a block. In the case just mentioned the train in questionwould undoubtedly be restricted to its minimum speed before it wouldreach the other train, thus affording full protection. If, however, thetra n which backed up would have backed upso far as to entirely leavethe second block in' advance before the train in question is restrictedto its minimum speed, that is passed over four active track elements inthe particular embodiment illustrated, the train in question would bereleased and a collision at low speed might occur. These last mentionedcircumstances are, however, not very aptto happen under actual workingconditions, bearing in mind that wayside block signalling on doubletrack railroads do not provide for such train movements and suchmovements are ordinarily not permitted or contemplated.

Another characteristic feature of the invention is that, after a trainhas traveled completely through a caution block, without reoperation.The significance of this will be appreciated when it is observed thatthe track elements in a block occupied by a train may be either in theclear or stopping condition depending 'upon whether or not the blocknext in advance is unoccupied or occupied. Consequently, a trainentering an occupied block may encounter track elements either in theclear or stopping condition, and it will be evident that, from thestandpoint of safety, the train coming into such occupied block shouldnot be able to receive an automatic restoration by the influence of suchtrack elements, inasmuch as said restoration is not proper in view ofthe train immediately ahead, but may occur in the event that the. blocknext ahead is not occupied. It will be noted that the manual restorationis possible only after the cam has traveled to its minimumspeedpositionfassuring that the train has reduced speed before such manualreset is possible. Thus, the manual resetting device may be in thelocomotive cab, directly accessible to the engineer, since it iseffective only in case the speed has been reduced to a safe minimum.However, in order to assure that the engineer will have to manipulatethis resetting device each time, and can not fasten it down, thearrangements shown and hereinbefore described are provided such thatoperation of the resetting device results in a brake application. Inthis connection. it will. be observed that the brake controlling; deviceK may be constructed to have a brief inherent time interval or delay inits operation, so that, while the engineer can not permanently fastenthe resetting device in its 'operated position, he is able. tomanipulate it without producing an actual brake application.

l Vhile it is contemplated that the system of speed control embodying;this invention will preferably be employed in connection with the usualtrackway fixed signals, signaling devices are provided as hereinbeforeexplained, to inform the engineer when he enters a caution block, andalso to advise him when his speed has approached the critical limitingspeed. The signaling devices, comprising lamp G'and bell 8 inconjunction 'withthe trackway signals enable the engiiSfril'l' its:active condition at the time.

3. In a train control system-comprising a lneer to determine Whether ornotian initiation: of the speed control apparatus takes place in theregular way near the entrance to a block, or'occurs at an intermediatepoint in the block on account of a change in tra'liic conditions in theneat'block inadvance from clear to danger.

In order to disclose the nature of the invention, one specificembodimentthereof has been shown and-described; but it will be1ob vious that manymodifications and adaptations of this specific structure may be employedin practice without departing, from the underlying principles and modeof op 'eration of the invention. For example, while influencecommunicating means operating inductively have been-shown, and onespecific typeoi a brake control apparatus, dependent upon failure of the:vehicle to conform witlna prescribedvariable speed limit, otherspecificmeans of asimilar character,:t'or the-same purpose maybe used; and'ldesire to have it understoodthat the particular parts and circuits shownand described are susceptible: of modification, adaptation, oruaddition,depending upon the nature and extent of the train regulation desired,aswellvas' thewparticular character 01" means to be employed, and thatthe invention is not intended to bein any way limited by 'the specificdisclosure herein made.

What I claim is 1. In a train control system For railways divided intoblocks comprising a cyclic device which will enforce a: graduallydecreasing permissive speed depending on the position of the train inthe block when initiated, means wholly on the vehicle for automatical-1y restoring said device when the train has traveled a predetermineddistance. after said device has been initiated, and meanslocated at aplurality of pointsalong the track for at times initiating; said deviceand at other tims preventing said vehicle carried restoring means fromautomatically restoring said device.

2. In a train control system comprising a permissive speed deviceadapted to enforce i a restricted speed When initiated by its passageover-an active trackWa-y device, a plurality of trackway devices spacedpredetermined distances apart alongr the-'trackway each adapted to be inan active or inactive condition, and means Wholly on the train andassociated With said permissive speed device for restoring said deviceonly after the train has traveled said predetermined distance after saiddevice has been initiated and upon its passage by. a trackway devicewhich is in its inactive condition at the time 'but which is incapableof restoring said device it said last mentioned traekivay devicepermissive speed device on the vehicle which if initiated willconditionally restore itseit after yarious predetermined distances oftravel, and an-apparatus partly on the vehicle and partly at pointsalong; the track for initiating said. device, allowing said. device torestoreit-self ormaintaining said. device inv operation when;passingsuch point dependent-npon tralfic conditions in advance.

in a train controlsystem of the cyclic typecomprising a permissive.speed device adapted to be initiated ctor entorcing restricted speedsautomatic means for restorinemsaid device when danger conditions. inadvance clear up, and manual means for restoringsai (1- device onlyoperative when the speed has been i'QStTlCtGd-"t/OEZL predeterminedextent.

. In an automatic train control system, the combinationlot signalingmeans; for indicating clear and caution, respectively,inifluencegreceiving means on the vehicleator cnanging'. the indicationof said signaling means from its normal clear indicating to itseautionindicatingcondition, and other car-carried vmeans for ,ehangingtheindication from caution to' clear after a predetermined distance of:travel ,ot the vehicle un less an intervening control influence has beenreceived.

(3. An automatic train control system comprising' a cyclicsignaling-means iornindicating' l-favorable and unfavorable tratlicconditions-means to receive control influences' rfrom the trackwav forinitiating said cyclic device and indicating; unfavorable in stead oifavorable trafiic conditions, [and means, governedibysaid cycliejdeyicefor restoringitto itsnormal favorable trafiic con- ClltlODS: after. apredetermined distance of travel of the vehicle effective if nointervenone part ct block, means for picking up the other of said relays when acar occupies another-part oi the block provided the first mentionedrelay is energized at the time.

and an electro-responsive device operated ointly by said relays.

j 8. Car-carried apparatus for automatic train control systemscomprising, a plurality of devices of the stick type, means for pickingup one of saidstick devices at one part of a block; means. for pickingup the other of said stick devices providing the first device is in itspick-up position when the train passes anotherpointinthe block, and

'meansgoverned by said two devices.

39. A train control systemmmnprising, a cyclic device, car-carr1ed;meansfor restrictfing; the speed. of the vehicle in accordance with? thedistance -'travel ed aften said device has been initiated, means carriedWholly on the vehicle for restoring said speed restricting meansoperative when an intermediate speed limit is being enforced, andtraclrway devices located at a plurality of points along the trackadapted to initiate said apparatus under danger tratlic conditions itsaid device has not already been initiated, prevent it from beingrestored under dangerous traflic conditions ahead, and allowing it to berestored under clear tratiic conditions ahead.

10. In a train control system of the cyclic type comprising a permissivespeed device, traflic controlled means for initiating said device,automatic means for resetting said device to its initial position, andmeans operable manually. only and effective only after the speed of thetrain has been restricted to a certain minimum for resetting saiddevice.

11. An automatic train control system comprising, a stick relay having apick-up and a stick circuit, a second relay having a pick-up circuitincluding a front contact of said first-mentioned relay and having asticlr circuit, means for closing the first-mentioned pick-up circuitafter a predetermined distance or movement of the vehicle from apredetermined point along the trackway, means for closing the pick-upcircuit of the second relay providing the first relay is al.- readypicked up after a further distance of movement of the vehicle along thetrackway, and train control means governed by said second mentionedrelay.

12. In a train control system, car-carried apparatus comprising a camadapted to be driven from the wheels of a vehicle, means for disengagingthe driving connection for said cam, a visual signal and an audible signal connected in series, and means for shunt- -1ng said visual signalwhen said cam is in driving relation with said wheels.

13. Car-carried apparatus for automatic train control systemscomprising, a cyclic device adapted to be initiated by trackway devices,and means for automatically restoring said device if less than apredetermined number of influences are received from suitable trackwaydevices in a predetermined distance of travel.

14:. In an automatic train control system, the combination of a cyclicdevice normally held in a maximum permissive speed condition which ifinitiated gradually assumes more restrictive speed conditions, meanspartly on the vehicleand partly along the track for initiating saidcyclic device, and means for restoring said device or continuing it inoperation to further restrict the speed of the vehicle at any one of aplurality of points in its travel from its maximum to its minimumpermissive speed condition, including spaced traclrway devices capableof transmitting one kind of control influence only. I

15. In an automatic train control system, the combination of a cyclicdevice normally held in a maximum permissive speed condition which ifinitiated gradually assumes more restrictive speed conditions, meanspartly on the vehicle and partly along the track for initiating saidcyclic device, and means for restoring said device or continuing it inoperation to further restrict the speed of the vehicle at any one or" aplural ity of points in its travel from its maximum to its minimumpermissive speed condition, including spaced trackway devices onlycapable of transmitting control influences under dangerous trafficconditions ahead 16. An automatic train control system comprising, apermissive speed device normally in its maximum permissive speedcondition, means partlyon the vehicle and partly along the trackway forinitiating said device to set up gradually decreasing permissive speedlimits, and means governed by said device for restoring it to itsinitial condition when reaching a predetermined intermediate speed limitunless a control influence is transmitted from the trackWay to thevehicle during the time said device changes from its maximum to saidintermediate speed condition.

17. An automatic train control system comprising, a permissive speeddevice which sets up a maximum permissive speed when in its normalcondition and which if initiated sets up gradually decreasing speedlimits in accordance With the movement of the vehicle along thetraclrway, automatic means on the vehicle tending to restore said deviceat intermediate points between the maximum and the minimum permissivespeed, and trackway means adapted to initiate said device and prevent itfrom being automatically restored when danger traflic conditions aheadexist.

18. An automatic train control system comprising, a permissive speeddevice which sets up a maximum permissive speed when in its normalconditions and which if initiated sets up gradually decreasing speedlimits in accordance with the movement of the vehicle along thetrackway, means for automatically restoring said device in accordancewith traffic conditions ahead, and manually operable means for restoringsaid device effective only it operated while said permissive speeddevice is in its minimum permissive speed condition.

19. An automatic train control system comprising, a permissive speeddevice which sets up a maximum permissive speed when in its normalcondition and which if initiated sets up gradually decreasing speedlimits in accordance with the movement of the vehicle along thetrackway, means wholly on the vehicle for restoring said device, meanspartly on the vehicle and partly along the trackway for initiating saiddevice and for preventing it from being restored bysaid vehicle carriedrestoring means in accordance with trafiic conditions ahead. and meansfor giving" an indication when said device is in its initiated conditionand for giving another distinctive indication when it is in its restoredcondition.

20. An automatic train control system comprising, a permissive speeddevice on a railway vehicle normally maintained in its maximum speedposition and which it initiatednioves to more restrictive speedconditions in accordance with the movement of the vehicle, meansgoverned by said device causing" a primary and a secondary restoringoperation, the successive operations of which without an interveninginitiating operation Will restore said'devi'c'e to its initial norinalcondition, and means'partly on the vehicle and partly along the'trackwayfor producing initiating operations at a plurality of points in eachblock under dangerous trafiic conditions ahead, whereby the permissivespeed device is initiated to move from its maximum speed position to anintermediate speed position or the permissive speed device is permittedto continue in operation from an intermediate speed position to a lowerspeed position in response to such an initiating operation. i

21. Means for effecting initiation and restoration respectively of speedcontrol apparatus for auton'iatic train control systems comprising,car-carried means for initiating said speed control apparatus upon thereception of a control infiuenceby suitable infiuence receiving :meanstransmitted from the trackway near the entrance of .a block,

of the intermittent inductive type in whichv control influencescorresponding to danger ous traffic conditions ahead only aretransmitted from the trackway to the vehicle, the combination optcar-carried apparatus including a permissive speed device which itinitiated by such control influences aplurality of times in successionrestricts the speed of the train to a value depending on the number oftimes it has been initiated, and which device if initiated isautomatically restored ii thetrain travelsa predetermined distancewithout receiving such a control influence, said apparatus efi'ecting anautomatic brake application of the actual speed of the train exceeds thepermissi ve'speied, and a plurality of spaced trackway devices eachtransmitting a controlinfiuence to the car-carried apparatus underadverse trafiic conditions ahead when the train 'passessuch device,whereby the train is restricted to its lowest permissive speed value itthe train passes the requisite number of active trackway devices and isautomatically released after the speed has been :onlyrestricted to anintermediate value it traffic conditions ahead clear up in the meantime.i

i In testimony whereof '1 hereto. affix my signature. r

CHARLES s. BUs uE L.

